1. Field of the Invention
The present invention relates to a small computer system interface (SCSI) device capable of breakdown prediction and self-examination, and further relates to a breakdown prediction and self-examination method by this SCSI device. More specifically, the invention relates to a SCSI device capable of breakdown prediction and self-examination, and further relates to a breakdown prediction and self-examination method by this SCSI device which increases overall system performance by reducing the load of a master processor and SCSI bus, by reporting to the master processor only when necessary, after an I2C processor reads the status of the SCSI device.
2. Description of the Related Art
According to increased system speed and emphasis on service availability of a system, the stability of the SCSI device has an important effect upon the overall system performance. Generally, monitoring the operation environment, such as the driving status of the SCSI device, temperature, power, etc. in the SCSI back panel is performed by two methods. One method is to report to a main processor the predictable mechanical failure of the SCSI device, having a Self-Monitoring Analysis and Report Technology (SMART) function, through the SCSI bus. The other method is to poll, periodically, the SCSI device status by the use of a SCSI command (diagnosis command transmission).
An exemplary SCSI back panel comprises a temperature sensor, which monitors the SCSI device temperature, a power sensor, which monitors the SCSI device power, an I2C controller, which accesses the temperature and power information from the temperature sensor and power sensor, an I2C master processor, to which is reported the information about the temperature and power through the I2C bus from the I2C controller, and which sends the command to control the temperature and power of the temperature and power sensor to the I2C controller through the I2C bus. Since the temperature sensor, the power sensor, I2C controller, etc., are not contained within the SCSI device, all monitoring for the operation environment and the operation status about the SCSI device within the SCSI back panel is performed outside the SCSI device. In other words, a prior art method of monitoring the SCSI device status is not the analysis of SCSI device itself but the environment analysis around the SCSI device, and the monitoring accuracy is therefore low. Also this method decreases the system performance if monitoring time for the SCSI device status increases. This causes a decrease in efficiency of monitoring the SCSI device status, because this method limits the amount of monitoring time.
Because the SCSI device doesn't contain the temperature and the power sensor, and because it has limitation in its ability to find the hardware problem in the SCSI device, this method makes the system performance low by adding the load of the SCSI bus and the processor. Because there is no I2C interface within the SCSI device, the SCSI device status can be reported through the SCSI bus only.
Examples of known systems for performing diagnosis on a SCSI device are provided by U.S. Pat. No. 5,033,049 to Don S. Keener et al. entitled On-Board Diagnostic Sub-System For SCSI Interface and U.S. Pat. No. 5,475,814 to Yasuham Tomimitsu entitled Self Diagnosis Of A SCSI Controller Through An I/O Port For Data Transmission/Data Reception Modes Of Operation.